PROJECT SUMMARY Blacks in the United States have a higher incidence of end-stage kidney disease than the general population; much, but not all, of this excess risk is attributed to variants in the ApoL1 gene. The ApoL1 Long-term Kidney Transplantation Outcomes (APOLLO) Network was established to address the role, if any, of ApoL1 testing in kidney transplantation. The APOLLO Network will enroll and genotype approximately 700 LD and 1600 DD while tracking outcomes for LD and recipients. All participants will have the option to receive their ApoL1 test results after enrollment ends. The APOLLO Network has the potential to increase understanding of kidney health disparities among Blacks and improve transplantation outcomes. However, the introduction of ApoL1 testing risks stigmatizing Black organ donors, reducing the number of Black LD, and worsening disparities. It also raises a series of ethical questions about clinical practices: who to test, how to use test results, and with whom to share results. We propose a 3-year ancillary R01 project that will be relevant not only to the APOLLO Network, but to future projects involving genetic testing that targets Black patients. Our team members serve on the APOLLO steering committee and community advisory council and have engaged diverse stakeholders in developing the following aims and research questions (RQ): Aim 1. Answer RQ1: Which factors influence participants' evaluation of competing ApoL1 testing clinical practices and engagement with ApoL1 test results? a. Administer a web-based survey to APOLLO participants that assesses the acceptability of competing ApoL1 clinical practices. b. Determine factors that predict APOLLO participants' attitudes toward diverse ApoL1 clinical policies, and whether participants access their ApoL1 test results. Aim 2. Answer RQ2: What are participant experiences with the return of ApoL1 testing results? a. Administer a survey to 600 participants who access their ApoL1 test results to assess comprehension of information, satisfaction or regret with testing, and intentions to use this information. b. Conduct qualitative interviews to explore the reasons behind participants' decision whether to receive ApoL1 test results, and examine the impact of these decisions on participants and family members. Aim 3. Answer RQ3: Is it feasible to use a Delphi panel process to obtain an informed consensus among diverse stakeholder groups on ApoL1 testing clinical practices? a. We will use a Delphi panel process with representation from all DD family members, DD recipients, LD, LD recipients, and transplant personnel.